GB189905396A - Improvements in and connected with Photographic Cameras. - Google Patents

Abstract

5396. Constan, M. March 11. Cameras; change-boxes ; shutters.- Consists in a combination of a camera, a plate-changing arrangement, and a shutter, of which the latter may be automatically set by the plate-changing device. The plates &c., in suitable sheaths p<2> to p<24>, are pressed forward by springs r. To remove the front plate (after exposure) from front to back, the camera is held with the lens upward as in Fig. 1, and a hinged side is pulled out by means of the ring y'. Hooked rods pull out the front plate, and allow it to fall into the position shown at p<1>, so that, when the hinged side is pushed in, the plate p<1> is placed at the back of the pile of plates. A disc to show the number of exposures is actuated by a pawl jointed to the hinged side. A hooked lever c, controlled by a cam on the disc n<1>, locks the hinged side when all the plates have been exposed. A cord y, fixed at one end to the camera and at the other to the shutter, passes round a pulley on the hinged side, and automatically sets the shutter by the movement of changing a plate. The shutter, Fig. 4, consists of two slides j<1> and j<11> (with exposure apertures), one of which opens the lens, and then releases the second slide, which closes the lens. The two slides are actuated by spiral springs r<1>, r<2>. By pressing the knob d<11>, the latch d' is lifted from the stop b<4> and releases the front slide j<1>, which moves to the left till its aperture is opposite the lens. At the same time a stop b<1> on this slide strikes the lever l<2>, which liberates a spring- pressed pneumatic piston (not shown). This piston moves forward at a speed regulated by the area of the escape apertures, and at the end of its stroke liberates the slide j<11>, which closes the lens opening. The area of the escape apertures is regulated by a piston valve p<11> which uncovers more or less of the apertures t<1>, t<2>, &c. through which the air escapes from the speed-controlling cylinder. For time exposures, the mechanism is altered, so that the release of the second slide j<11> is not automatic, but is effected at any required interval by hand.